Recommended System Management
Alternative: X4283
128K
16K x 8 Bit
X24128
400kHz 2-Wire Serial EEPROM with Block Lock™
DESCRIPTION
FEATURES
• Save critical data with programmable block lock
protection
—Block lock (0, 1/4, 1/2, or all of EEPROM array)
—Software write protection
The X24128 is a CMOS Serial EEPROM, internally
organized 16K x 8. The device features a serial inter-
face and software protocol allowing operation on a
simple two wire bus.
—Programmable hardware write protect
• In circuit programmable ROM mode
• 400kHz 2-wire serial interface
—Schmitt trigger input noise suppression
—Output slope control for ground bounce noise
elimination
• Longer battery life with lower power
—Active read current less than 1mA
—Active write current less than 3mA
—Standby current less than 1µA
• 2.5V to 5.5V power supply version
• 32 word page write mode
—Minimizes total write time per word
• Internally organized 16K x 8
• Bidirectional data transfer protocol
• Self-timed write cycle
—Typical write cycle time of 5ms
• High reliability
Three device select inputs (S –S ) allow up to eight
devices to share a common two wire bus.
0
2
A Write Protect Register at the highest address location,
FFFFh, provides three write protection features: Soft-
ware Write Protect, Block Lock Protect, and Program-
mable Hardware Write Protect. The software write
protect feature prevents any nonvolatile writes to the
device until the WEL bit in the write protect register is
set. The Block Lock protection feature gives the user
four array block protect options, set by programming two
bits in the write protect register. The programmable
hardware write protect feature allows the user to install
the device with WP tied to V , write to and Block Lock
CC
the desired portions of the memory array in circuit, and
then enable the In Circuit Programmable ROM Mode by
programming the WPEN bit HIGH in the Write Protect
Register. After this, the Block Locked portions of the
array, including the Write Protect Register itself, are per-
manently protected from being erased.
—Endurance: 100,000 cycles
—Data retention: 100 years
• 8-lead XBGA
Xicor EEPROMs are designed and tested for applica-
tions requiring extended endurance. Inherent data
retention is greater than 100 years.
• 14-lead SOIC
BLOCK DIAGRAM
Data Register
Serial EEPROM Data
and Address (SDA)
Y Decode Logic
Command
Serial Eeprom
Array
Page
Decode
Logic
SCL
Decode
16k X 8
and
Control
Logic
4k X 8
4k X 8
Block Lock and
Write Protect
Control Logic
S
S
S
2
1
0
Write
Protect
Register
Device
Select
Logic
8k X 8
Write Voltage
Control
WP
Characteristics subject to change without notice. 1 of 16
REV 1.1 9/8/00
www.xicor.com
XICOR [ XICOR INC. ]
